This invention relates generally to mass data storage devices and, more particularly, to solid-state random access memory (RAM) mass data storage devices for video server applications.
Video-on-demand will provide home television viewers the ability to watch movies of their choice at any time of the day in the comfort of their homes. Centrally located video servers will store current popular movies and allow thousands of viewers simultaneous access to these movies at any one time. Less popular current movies or older movies will be downloaded to the video server upon demand. Home television sets will be connected to the video servers by phone lines, using either copper or fiber optic cables. Each viewer will have independent video cassette recorder (VCR)-like control over the movie being watched.
Each video server will include some type of mass data storage device for storing the movies. Hard disk or optical disk storage devices could be used, but the latency times are too long for independent VCR-like control of numerous movies by thousands of viewers. Magnetic tape does not allow for multiple accesses of a movie at different times or independent VCR control of a movie by different viewers. Therefore, the mass data storage device will likely be a solid-state RAM storage device. However, solid-state RAM mass data storage devices still do not provide the high densities and large memory capacities that are required by video servers, even though refinements in semiconductor fabrication techniques have reduced the unit cost and increased the unit density of solid-state RAM memory devices. Accordingly, there has been a need for a high-capacity solid-state mass data storage device for video server applications. The present invention clearly fulfills this need.